Method and system for browsing a low-resolution image

ABSTRACT

A system for retrieving information from a document. The system includes a document model representative of the document having a plurality of data structures representative of components within the document and a thumbnail image registered with the document model. The registration is accomplished by mapping selected coordinates within the thumbnail image to a data structure selected from the plurality of data structures. In this manner, a user can interact with the thumbnail image coordinates to retrieve data from the document as a function of the components mapped to those coordinates. In a further embodiment of the invention, the retrieved information may be streamed to a word-at-a-time display. This is particularly useful when used in connection with the display of low-resolution images on hand-held devices.

FIELD OF THE INVENTION

This invention relates generally to the field of information displayand, more particularly, relates to a method and system for browsing orrapidly accessing the contents of a low-resolution image.

BACKGROUND OF THE INVENTION

It is known in the computer art to use a thumbnail image to provide arepresentation of a full-sized image stored on a computer. In itscurrent embodiment, the thumbnail image is merely a low-resolutionversion of the full-sized image created, for example, by sub-samplingthe full-sized image. Associated with the thumbnail image is a link,such as a hyperlink. The link may be used to access the computer storagelocation of the full-sized image counterpart of the thumbnail imagewhereby the full-sized image may be retrieved and displayed.

To retrieve the full-sized image, a user is typically required tointeract with the displayed thumbnail image. This interaction is oftenaccomplished by positioning a cursor over a portion of the thumbnailimage. Once the cursor is positioned over the thumbnail image, thethumbnail image may be selected, for example, by clicking an appropriatemouse button. In response to this interaction, the applicationassociated with the display of the thumbnail image, such as a Webbrowser, initiates the retrieval of the entire full-sized image from itsstorage location. Once retrieved, the entirety of the full-sized imageis available for display.

Methods for creating thumbnail images are also well known in the art. Byway of example, Microsoft's “FRONTPAGE” brand Web site creation andmanagement tool provides the software needed to create thumbnail images.Using the “FRONTPAGE” brand editor, the user selects a full-sized imageon a page and chooses “Auto Thumbnail” from the “Tools” menu. Inresponse to this selection, the “FRONTPAGE” brand editor creates thethumbnail image as well as a hyperlink to the full-sized image. Once thethumbnail and link are created, the full-sized image remains accessibleto the end user through activation of the thumbnail image in the mannerdescribed above.

The use of thumbnail images to represent full-sized images has manyadvantages. For example, a primary advantage associated with the use ofthumbnail images is a conservation of system resources, such as networkbandwidth, CPU processing time, etc. This conservation of systemresources results from the low-resolution nature of the thumbnail imagethat minimizes the amount of information that is required to beinitially downloaded and displayed. Accordingly, a system canaccommodate the downloading and display of multiple thumbnail imagesrepresenting multiple full-sized images, such as pages of a document,using relatively smaller amounts of system resources when compared tothe amount of system resources required to present the same informationin its full-sized format.

While the representation of full-sized images through the use oflow-resolution thumbnail images provides the advantages noted above,there still remains drawbacks associated with their use. For example,the low-resolution thumbnail image representation of the full-sizedimage is often of such poor quality that a user is not able to discernwhat information is actually contained within the counterpart full-sizedimage. This is particularly true of images containing text andassociated high frequency information. Furthermore, since activation ofthe thumbnail image results in the downloading of the entire filecomprising the full-sized image, the primary benefit associated with theuse of thumbnail images, namely conserving system resources, iseffectively defeated.

Accordingly, a need exists for an improved method and system for using athumbnail image to display information. In particular, a need exists fora method and system for use in browsing information presented to a userin the form of a low-resolution image. This is especially desirable foruse in connection with hand-held devices, such as personal digitalassistants, where there is limited screen real-estate.

SUMMARY OF THE INVENTION

In accordance with this need, the invention is generally realized in asystem for retrieving information from a document. The system includes adocument model having a plurality of data structures representative ofthe components within the document and a thumbnail image registered withthe document model. The registration is accomplished by mapping selectedcoordinates within the thumbnail image to a data structure selected fromthe plurality of data structures. A user can interact with the thumbnailimage coordinates to retrieve information from the document as afunction of the component(s) mapped to those coordinates. In a furtherembodiment of the invention, the retrieved information may be streamedto a word-at-a-time display while the thumbnail image is altered toprovide a user with an indication of the context of the streamedinformation.

In this manner the invention allows a user to interact with thelow-resolution thumbnail to extract detailed information from a documentwithout having to view the original full-resolution image of thedocument. Furthermore, the invention supplies navigation context toword-at-a-time displays.

Additional features, advantages and objects of the invention will bemade apparent from the following detailed description of illustrativeembodiments which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

While the appended claims set forth the features of the presentinvention with particularity, the invention, together with its objectsand advantages, may be best understood from the following detaileddescription taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a block diagram illustrating an exemplary computer system onwhich the present invention resides;

FIG. 2 is a block diagram illustrating a registration between a DocumentModel and a smart thumbnail in accordance with the present invention;

FIG. 3 is a flow chart diagram illustrating a method for creating thesmart thumbnail of FIG. 2;

FIG. 4 is a flow chart diagram illustrating a method for retrievinginformation using the smart thumbnail of FIG. 2;

FIG. 5 is a screen shot of an exemplary smart thumbnail and anassociated word-at-a-time display created in accordance with the presentinvention;

FIG. 6 is a further representation of the exemplary smart thumbnail andthe associated word-at-a-time display of FIG. 5; and

FIG. 7 is flow chart diagram illustrating a method for streaming data tothe word-at-a-time display illustrated in FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

Turning to the drawings, wherein like reference numerals refer to likeelements, the invention is illustrated as being implemented in asuitable computing environment. Although not required, the inventionwill be described in the general context of computer-executableinstructions, such as program modules, being executed by a personalcomputer, hand-held computer, or the like. Generally, program modulesinclude routines, programs, objects, components, data structures, etc.that perform particular tasks or implement particular abstract datatypes. Moreover, those skilled in the art will appreciate that theinvention may be practiced with other computer system configurations,multi-processor systems, microprocessor based or programmable consumerelectronics, network PCs, minicomputers, mainframe computers, and thelike. The invention may also be practiced in distributed computingenvironments where tasks are performed by remote processing devices thatare linked through a communications network. In a distributed computingenvironment, program modules may be located in both local and remotememory storage devices.

With reference to FIG. 1, an exemplary system for implementing theinvention includes a general purpose computing device in the form of aconventional personal computer 20, including a processing unit 21, asystem memory 22, and a system bus 23 that couples various systemcomponents including the system memory to the processing unit 21. Thesystem bus 23 may be any of several types of bus structures including amemory bus or memory controller, a peripheral bus, and a local bus usingany of a variety of bus architectures. The system memory includes readonly memory (ROM) 24 and random access memory (RAM) 25. A basicinput/output system (BIOS) 26, containing the basic routines that helpto transfer information between elements within the personal computer20, such as during start-up, is stored in ROM 24. The personal computer20 further includes a hard disk drive 27 for reading from and writing toa hard disk, not shown, a magnetic disk drive 28 for reading from orwriting to a removable magnetic disk 29, and an optical disk drive 30for reading from or writing to a removable optical disk 31 such as a CDROM or other optical media.

The hard disk drive 27, magnetic disk drive 28, and optical disk drive30 are connected to the system bus 23 by a hard disk drive interface 32,a magnetic disk drive interface 33, and an optical disk drive interface34, respectively. The drives and their associated computer-readablemedia provide nonvolatile storage of computer readable instructions,data structures, program modules and other data for the personalcomputer 20. Although the exemplary environment described herein employsa hard disk, a removable magnetic disk 29, and a removable optical disk31, it will be appreciated by those skilled in the art that other typesof computer readable media which can store data that is accessible by acomputer, such as magnetic cassettes, flash memory cards, digital videodisks, Bernoulli cartridges, random access memories, read only memories,and the like may also be used in the exemplary operating environment.

A number of program modules may be stored on the hard disk, magneticdisk 29, optical disk 31, ROM 24 or RAM 25, including an operatingsystem 35, one or more applications programs 36, other program modules37, and program data 38. A user may enter commands and information intothe personal computer 20 through input devices such as a keyboard 40 anda pointing device 42. Other input devices (not shown) may include amicrophone, joystick, game pad, satellite dish, scanner, or the like.These and other input devices are often connected to the processing unit21 through a serial port interface 46 that is coupled to the system bus,but may be connected by other interfaces, such as a parallel port, gameport or a universal serial bus (USB). A monitor 47 or other type ofdisplay device is also connected to the system bus 23 via an interface,such as a video adapter 48. In addition to the monitor, personalcomputers typically include other peripheral output devices, not shown,such as speakers and printers.

The personal computer 20 may operate in a networked environment usinglogical connections to one or more remote computers, such as a remotecomputer 49. The remote computer 49 may be another personal computer, aserver, a router, a network PC, a peer device or other common networknode, and typically includes many or all of the elements described aboverelative to the personal computer 20, although only a memory storagedevice 50 has been illustrated in FIG. 1. The logical connectionsdepicted in FIG. 1 include a local area network (LAN) 51 and a wide areanetwork (WAN) 52. Such networking environments are commonplace inoffices, enterprise-wide computer networks, intranets and the Internet.

When used in a LAN networking environment, the personal computer 20 isconnected to the local network 51 through a network interface or adapter53. When used in a WAN networking environment, the person computer 20typically includes a modem 54 or other means for establishingcommunications over the WAN 52. The modem 54, which may be internal orexternal, is connected to the system bus 23 via the serial portinterface 46. In a networked environment, program modules depictedrelative to the personal computer 20, or portions thereof, may be storedin the remote memory storage device. It will be appreciated that thenetwork connections shown are exemplary and other means of establishinga communications link between the computers may be used.

In the description that follows, the invention will be described withreference to acts and symbolic representations of operations that areperformed by one or more computers, unless indicated otherwise. As such,it will be understood that such acts and operations, which are at timesreferred to as being computer-executed, include the manipulation by theprocessing unit of the computer of electrical signals representing datain a structured form. This manipulation transforms the data or maintainsit at locations in the memory system of the computer, which reconfiguresor otherwise alters the operation of the computer in a manner wellunderstood by those skilled in the art. The data structures where datais maintained are physical locations of the memory that have particularproperties defined by the format of the data. However, while theinvention is being described in the foregoing context, it is not meantto be limiting as those of skill in the art will appreciate that variousof the acts and operation described hereinafter may also be implementedin hardware.

In accordance with the invention, a rendered view of a document in theform of a bitmap image or “smart thumbnail” is provided as arepresentation of a document stored within the computer system,hand-held computer, or the like. In this manner, it is possible for auser to interact with the smart thumbnail to gain access to theorganization, components and associated behavior of the document.Additionally, the rendered view of the document can be generated usinginformation in the associated document model as an additional way topresent to the user meaningful information about the document.

To allow the user to gain access to the organization, components andassociated behavior of the document, the smart thumbnail is registeredwith the document. More specifically, the smart thumbnail is registeredwith a data structure representative of the document genericallyreferred to as a “document model.”

The document model consists of data structures containing datarepresentative of components such as text, images, vector graphics,and/or multimedia components that are composited together to form theunderlying document. The document model may also includes datastructures representative of the component layout that describe how thecomponents that comprise the document are spatially arranged in therendered image of the document. The component layout may also includedata representative of presentation information that describes thepreferred ordering of the components when they are sequentiallypresented.

As illustrated in FIG. 2 and by way of example only, a simple textdocument 70 can be described using a document model 72 having componentsof increasingly more specific semantic units. In the example provided,the components are pages, blocks of text, lines of text, and words.Preferably, the highest component level is the text document itselfwhile the lowest component level is words. In this manner, the document70 can be described as having a number of page components (Page 1 . . .Page N), each page component can be described as having a number oftextual block components, e.g., paragraphs, (Text Block 1 . . . TextBlock N), each textual block component can be described as having anumber of textual line components (Line Block 1 . . . Line Block N), andeach textual line component can be described as having a number of wordcomponents (Word 1 . . . Word N). Preferably, the data structuresrepresentative of these components are each provided with an addresssuch that links may be used to gain access to the components on anindividual basis.

For registering the smart thumbnail image to the counterpart document,selected coordinates within the smart thumbnail image are mapped toselected components using layout information in the document model 72.By way of example, FIG. 2 illustrates a smart thumbnail image 74 that isa low-resolution image representative of the text document 70. The smartthumbnail may be registered with the document model by mapping: 1) allof the coordinates within the smart thumbnail 74 to a page componentselected from the document model 72; 2) coordinates defining a region 78within the smart thumbnail 74 representative of a paragraph to a textualblock component selected from the document model 72; 3) coordinatesdefining a region 82 within the smart thumbnail 74 representative of aline of text to a line block component selected from the document model72; and/or 4) coordinates defining a region 86 representative of a wordto a word component selected from the document model 72.

More specifically, as illustrated in FIGS. 2 and 3, the registration ofthe smart thumbnail 74 to the document model 72 may be performed bycreating in step 90 a full-sized bitmap image replica 88 of thedocument. Alternatively, in step 91, the full-sized bitmap image replica88 can be generated using the layout information in the document model72. Still further, the full-sized bitmap image replica 88 could begenerated using an internal representation of the document created, forexample, in the printing process.

Within the full-sized bitmap image 88, coordinates of the bits that arerepresentative of selected components from the document model 72 areidentified in step 92. For example, the coordinates of a rectangle inwhich reside those bits that together give the appearance of a word areidentified. In step 94, the identified coordinates are mapped to acorresponding component selected from the document model 72. Thismapping preferably provides the identified coordinates with a link tothe address of the components to which the coordinates are mapped.

Once the full-sized bitmap image has been mapped to all of the desiredcomponents, the smart thumbnail 74 low-resolution image is created instep 96 from the full-sized bitmap image 88. As will be appreciated bythose of skill in the art, the creation of the low-resolution image maybe performed by sub-sampling the full-sized bitmap image 88 using, forexample, a multi-resolution pyramid technique or the like. During thisprocess, the coordinates within the full-sized bitmap image 88 that aremapped to the components are translated to the scale of thelow-resolution image. In this manner, the smart thumbnail 74 isregistered to the document model 72. In FIG. 2, the layered pyramidcorresponds to different resolutions of the image of the associateddocument. The higher up the pyramid, the smaller the image becomes. Thesmallest image is shown as corresponding to the thumbnail.

For generating the bitmap image in accordance with step 90 of FIG. 3,various tools known in the art are available for use. For example,Optical Character Recognition (OCR) tools can be used in conjunctionwith document description formats to generate information pertaining topositions of text within a rendered image of a simple text document.Similar information may be generated using known document-processingtechniques which analyze a scanned document into a hierarchical set ofgroups without performing explicit OCR character recognition. Thispositional information may then be used to map the identifiedcoordinates to the appropriate semantic units selected from the documentmodel 72.

To allow a user to interact with the smart thumbnail 74, the smartthumbnail is presented on the display 47 associated with computer 70 ofFIG. 1. In this manner, a user can manipulate a display cursor, usingthe mouse 42, keyboard 40, or the like, to indicate a specific positionwithin the displayed smart thumbnail 74 for which more detailedinformation is desired to be retrieved. The smart thumbnail 74 can bepresented to the user in connection with any number of applicationprograms 36 such as, for example, an Internet browser application, aword processing application, a spreadsheet application, or like type ofapplication whose underlying function is information presentation.

For retrieving the detailed information related to the positioning ofthe cursor, the coordinate in the smart thumbnail 74 that underlies theposition of the cursor is determined as illustrated in step 100 of FIG.4. It will be appreciated that determining the coordinate in the smartthumbnail 74 underlying the position of the cursor likewise allows thelink to the component mapped to that coordinate to be identified asshown in step 102. Thus, using the identified link, the applicationdisplaying the smart thumbnail can issue a request in step 104 that thedata represented by the component associated with the identified link beretrieved for subsequent display to the user. Returning to FIG. 2 and byway of example, if the user were to position the cursor over thecoordinates that define the region 86 within the smart thumbnail 74,data represented by the page component, textual block component, textualline component, and/or word component can be retrieved and displayed tothe user. The information retrieved depends upon which of thecomponent(s) selected from the document model 72 were mapped to theregion 86.

From the foregoing, it will be appreciated that the use of smartthumbnails allows for the retrieval and viewing of information selectedfrom a document without having to download the entirety of thecounterpart document image. Thus, among other things, the subjectinvention has the advantage of improving upon the conservation ofresources normally associated with using thumbnails. This ability toretrieve parts of documents also has the advantage of allowing a user toquickly and efficiently discern what is contained in a documentcorresponding to an unreadable thumbnail image.

For displaying information retrieved from a text document, it ispreferred that a word-at-a-time display (WAATD) be used. WAATDs areknown in the art and are generally used to present one or more words asa text stream to a viewer in a small, restricted, stationary window. Forexample, Tenax Software Engineering provides a downloadable Java applet,entitled “Cornix,” for use in providing WAATDs on Web pages. Since WAATDallow text documents to be read without requiring a user to move theireyes, WAATDs have been seen to increase reading times by as much as 90%.

With reference to FIGS. 2,5 and 6, the displaying of data retrieved froma document model within a WAATD display 110 is preferably performed as afunction of the presentation information maintained in the documentmodel 72. The presentation information may be used to navigate theglobal hierarchy of the document to stream information to the WAATD 110.By way of example, as illustrated in FIG. 7, given a starting wordcomponent within the document model 72, preferably defined in step 120by the user positioning the cursor over a coordinate in the smartthumbnail, the presentation information may direct that each wordcomponent following and including the starting word component within thetextual line component that includes the starting word component bestreamed to the WAATD in steps 122-126. In steps 128-130, the streamingto the WAATD of the word components can then be repeated for the nexttextual line component. In steps 132-134, the streaming to the WAATD ofthe word components from each of the textual line components may berepeated for the next textual block component. In steps 136-138, thestreaming to the WAATD of the word components from each of the textualline components from each of the textual block component may then berepeated for the next page component.

Using the method illustrated in FIG. 6, all word components from thestarting word component to the last word component in the hierarchy ofthe document model may be streamed to the WAATD. It will be appreciated,however, that the streaming of word components to the WAATD need notcontinue until the end of the document. Rather, the streaming ofcomponents to the WAATD can be restricted to a delimiter reflecting anyunit of document organization. Furthermore, the speed and/or manner inwhich components are presented within the WAATD can be controlled as afunction of the type of component being streamed to the WAATD 110. Byway of example, titles could be presented relatively slower than bodytext or the font, color, etc. of the information displayed may bechanged in the WAATD to visually notify to the user that some uniquetype of information is being presented.

Further use of the document model may also be made for causing singlepages of the document to be controllably displayed to the viewer inthumbnail format while being used in connection with the WAATD 110. Asillustrated in FIG. 6, a first page component (Page 1) from the documentmodel may be displayed and, in response to a user interacting with aforward page control (FP) and a reverse page control (RP) the next orprevious page in the document, respectively, may be displayed. Forexample, to traverse from the second page component (Page 2) to thefirst page component (Page 1), the user would interact with the RPcontrol as shown in FIG. 6. An additional field 130 may also be used todisplay the page number thereby providing page context to the user. Thismanner of presenting information is particularly advantageous for use inconnection with PDAs and other handheld devices having a small amount ofdisplay real estate.

While standard WAATDs have the advantage of improving reading time,manufacturers remain reluctant to incorporate WAATDs into productsbecause readers find the use of WAATDs to be sometimes unsettling. Forexample, readers are often unable to discern from where in the documentthe streaming words are being extracted. Accordingly, WAATDs tend to bevery poor for understanding context relative to overall documentorganization and navigation. To solve this problem, a smart thumbnailmay be utilized in connection with the WAATD 110.

To provide context to the words being streamed to the WAATD 110, a smartthumbnail corresponding to the document from which the streaming wordsare being extracted may be manipulated so as to indicate to a readerwhere in the document the streamed text organizationally resides. By wayof example and with reference to FIG. 5, the smart thumbnail 74 can havethe coordinates corresponding to the word components that are streamedto the WAATD display change color, be highlighted, etc. 112. In thismanner, the smart thumbnail provides visual clues to the reader thatfunction to track the streaming of words to the WAATD.

The altering of the rendition of the smart thumbnail 74 for the purposeof tracking within the context of the smart thumbnail 74 the streamingof words to the WAATD 110 can be accomplished using standard functionsfrom a graphical interface, such as Microsoft's graphical deviceinterface (GDI). It will also be appreciated that the GDI functions canbe used to change the rendering of the smart thumbnail in response toother factors such as, for example, highlighting coordinates in thesmart thumbnail in response to a query performed on the underlyingdocument model.

More specifically, the rendering information required by the graphicalinterface functions for effectuating an alteration of the coordinates ofthe smart thumbnail may be stored as part of the document model 72. Inthis manner, the document model can be used to control the rendering ofthe thumbnail to highlight information, for example, using renderingrules such as “use the text block highest on the page and with theboldest font to highlight the title.” Using such control, differentcomponents can be rendered differently based on their type.

Still further, the WAATD may be used to in connection with a computer,personal digital assistant, or the like to display Web content retrievedfrom the internet. Preferably, the Web content, in the form of adocument model, is streamed to the WAATD one word component at a time asdescribed above. However, when the word component of the Web contentdocument model is further defined to be a hyperlink/button component,the WAATD display can vary the presentation of the hyperlink componentto allow a user to interact with the hyperlink component. For example,the WAATD may pause when such a component is displayed to allow the usertime to activate the hyperlink. The pausing of the display may continueuntil the user interacts with the link or otherwise notifies thegraphical user interface that the link is not of interest. Stillfurther, the display of the hyperlink may be caused to blink, flash,change color or otherwise visually attract the attention of the userwhen displayed in the WAATD.

In yet another embodiment, the display of the smart thumbnail may bealtered to indicate the presence of a hyperlink. For example, withreference to FIG. 5, one color (blue) could be used to indicate thecontext of the information streamed to the WAATD with the color changing(to red for example) over those contextual locations corresponding to astreamed hyperlink. In this manner, the user may click on theappropriately colored location of the thumbnail to invoke the hyperlink.Preferably, for hyperlinks that are proximate to one another, a means(such as using multiple colors for example) is used to differentiate therendering of the hyperlink locales within the thumbnail image to avoidwhat would appear to the user a one continuous hyperlink.

Still further, the document model may be used to control the order inwhich information is presented in the WAATD. For example, the first itemof information displayed to the viewer could be the nearest title to thelocation activated on the smart thumbnail, the first word of a paragraphwhich has been selected by a user, etc. Additionally, the WAATD can beused to cycle through lists or columns of data.

While the invention has been primarily described herein using a simpletext document as the exemplary document that is registered with a smartthumbnail, it will be appreciated by those of skill in the art that theinvention is not intended to be so limited. Accordingly, the inventiondescribed herein contemplates more complex document models wherein thecomponents may be divided into classes such as images, vector graphics,etc. as weal as text. As will be further appreciated, these additionalcomponents are preferably handled differently than textually basedcomponents during the rendering process. For example, images could bedisplayed in specialized viewers while vector graphics could beindependently redrawn thus avoiding the averaged out sampling of theimages that would result from the process used to create the smartthumbnail image.

In another preferred embodiment of the invention, the document that isregistered with the smart thumbnail is an Extensible Markup Language(XML) document. As will be appreciated by those of skill in the art, XMLprovides to authors of documents a way of marking up the content of thedocument using tags that function to semantically organize the document.Consequently XML provides a standard way to better communicate therelevance of the content of the document when the document is registeredwith the smart thumbnail. For example, using XML, text components withina document can be more specifically characterized using tags thatidentify the text components as titles, headings, etc. In particular,XSL has been developed in XML to describe document layout which can beused for describing document models. This is described in LEVEL 1DOCUMENT MODEL SPECIFICATION, VERSION 1.0, W3C Working Draft, Jul. 20,1998 which is incorporated herein by reference in its entirety.

In view of the many possible embodiments to which the principles of thisinvention may be applied, it should be recognized that the embodimentdescribed herein with respect to the drawing figures is meant to beillustrative only and should not be taken as limiting the scope ofinvention. For example, those of skill in the art will recognize thatthe elements of the illustrated embodiment shown in software may beimplemented in hardware and vice versa or that the illustratedembodiment can be modified in arrangement and detail without departingfrom the spirit of the invention. Therefore, the invention as describedherein contemplates all such embodiments as may come within the scope ofthe following claims and equivalents thereof.

1. A system for linking to a document, comprising: a document model,representative of the document, having a plurality of data structuresrepresentative of components within the document; and a thumbnail imageregistered with the document model such that selected coordinates withinthe thumbnail image are each mapped to a data structure selected fromthe plurality of data structures.
 2. The system as recited in claim 1,wherein the document is a text document and the components comprise oneor more page components, textual block components, textual linecomponents and word components.
 3. The system as recited in claim 1,wherein the document is an XML document.
 4. The system as recited inclaim 1, wherein the components comprise images.
 5. The system asrecited in claim 4, wherein the images comprise vector graphics.
 6. Thesystem as recited in claim 1, further comprising a word-at-a-timedisplay associated with the thumbnail image for displaying the datarepresented by selected components from the document model, thecomponents selected in response to interaction with the thumbnail. 7.The system as recited in claim 1, wherein the components areindividually addressable. 8-30. (canceled)
 31. A computer-implementedsystem for linking to a document on a computer having a memory,comprising: a document model stored in the computer memory,representative of the document, having a plurality of data structuresrepresentative of components within the document, wherein the documentis an XML document; and data representing a thumbnail image registeredwith the document model using XML tags of the XML document such thatselected coordinates within the thumbnail image are mapped to a datastructure selected from the plurality of data structures.
 32. The systemas recited in claim 31, wherein the components comprise images.
 33. Thesystem as recited in claim 32, wherein the images comprise vectorgraphics.
 34. The system as recited in claim 31, further comprising aword-at-a-time display associated with the thumbnail image fordisplaying the data represented by selected components from the documentmodel, the components selected in response to interaction with thethumbnail.
 35. The system as recited in claim 31, wherein components areindividually addressable.
 36. A computer-readable memory having thereoncomputer-readable data fields for linking a portion of a document to acorresponding portion of a thumbnail image of the document, the datafields comprising: a document model field containing document modeldata, the document model data being representative of the document andcomprising a plurality of data structures representative of componentswithin the document, wherein the document is an XML document; and animage data field containing image data representative of the thumbnailimage, wherein portions of the image data are registered withcorresponding portions of the document model data using XML tags of thedocument such that selected coordinates within the thumbnail image aremapped to a data structure selected from the plurality of datastructures.
 37. The computer-readable memory as recited in claim 36,wherein the components comprise images.
 38. The computer-readable memoryas recited in claim 37, wherein the images comprise vector graphics. 39.The computer-readable memory as recited in claim 36, wherein thecomponents are individually addressable.